Grain separators are employed to separate a stream of grain containing various types and sizes of grain into constituent parts. Typical grain separators are used to separate such grains as wheat, durum, oats, barley and rice.
A grain separator is described in Hauch, U.S. Pat. No. 5,335,792. The grain separator includes a drum that rotates about a horizontal axis. Grain of varying sizes or types is added through an inlet at one end of the drum. Small indentations formed on the cylindrical wall of the drum capture the individual grain particles, and as the drum rotates, these particles are lifted until the fall from the indentations into an interior trough. The trough may be so oriented as to capture grain particles of a given size range. Grain is moved from the inlet into the drum by means of a rotatable heliacal screw which typically is driven by an electric motor through linkage including a drive shaft. The end of the drum nearest the grain inlet is provided with an end face, and the grain inlet includes a spout that extends through the end face to convey grain to the drum. The drive shaft may be mounted through appropriate bearings at the grain inlet. To provide a suitable seal between the grain inlet, which is stationary, and the drum, which rotates, an annular seal commonly is provided between the inlet and the drum.
Annular seals of the type described are highly susceptible to failure if grain or other debris finds its way between the bearing surface of the seal and the end plate surface of the drum against which the seal slides, and it is necessary, when this seal fails, to replace the seal. In the past, this has required disassembly of the grain inlet from the housing structure that supports the drum, or removal of the drum itself, and either of these approaches may be time consuming and difficult to accomplish, leading to undesired loss of production.